Saliva collection is a procedure with increasing clinical importance. It is a non-invasive means to assess the activity of a variety of diseases and the level of certain drugs and hormones (Ferguson, "Current Diagnostic Uses of Saliva," J. Dent. Res. 66:420-424(1987)). Whole saliva is a mixture of fluids secreted by the salivary glands, but also contains fluids, debris and cells not originating in the salivary glands. Therefore, the analysis of the individual gland saliva is usually a more reliable procedure for diagnostic purposes then the analysis of whole saliva (Fox et al, "Xerostomia: Evaluation of a Symptom with Increasing Significance," J. Am. Dent. Assoc. 110:519-525(1985)).
Saliva can be collected in a resting or a unstimulated state, reflecting secretion during most of the day, or in a stimulated condition, emulating salivary gland stimulation by food. Depending on the degree of stimulation, submandibular-sublingual (SM/SL) glands contribute between about 30 and 60% of the total volume of saliva (Schneyer, "Source of Resting Total Mixed Saliva of Man," J. Appl. Physiol. 9:79-81(1956); Mason et al, "Salivary Glands in Health and Disease," London; W. B. Saunders, pp. 37-39(1975)).
While saliva secreted from the parotid glands is relatively easy to collect using established methods (Carlson et al, "The Relationship of Ptyalin Concentration to the Diet and to the Rate of Secretion of Saliva", Am. J. Physol. 26:169-177(1910)). There is no universally accepted method for the collection of secretions from SM/SL glands. This difficulty is best illustrated by the fact that most saliva collections for research purposes reported in the scientific literature are limited to parotid or whole saliva.
One way of collecting submandibular or sublingual saliva is to cannulate the excretory ducts of the respective glands (Mandel, "Sialochemistry in Diseases and Clinical Situations Affecting Salivary Glands," Crit. Rev. Clin. Lab. Sic. 12:321-366(1980)). However this procedure is invasive and painful, and requires special skills.
One alternative to collecting saliva by cannulation is to use a collector placed externally to the ducts' openings. Schneyer, "Method for the Collection of Separate Submaxillary and Sublingual Salivas in Man," J. Dent. Res. 34:257-261(1955), proposed a custom made collector of an acrylic material. Others including Henriques et al, "A Modified Method for the Collection Submaxillary and Sublingual Saliva," Oral Surg. 9:1124-1129(1961); Stephen et al, "A Modified Appliance for the Collection of Human Submandibular and Sublingual Salivas" Arch. Oral Biol. 23:835-837(1978); and Parr et al, "A Modified Segregator for Collection of Human Submandibular and Sublingual Saliva," Arch. Oral Biol. 29:69-71(1984) made several modifications to custom made acrylic collectors. A major disadvantage associated with such custom made collectors is the amount of time and effort needed to construct each collector for individual subject use.
Although custom made devices made of impression materials (Morse et al, "Stress, Meditation and Saliva: A Study of Separate Salivary Gland Secretions in Endodontic Patients," J. Oral Med. 38:150-160(1983); McCarthy et al, "A Method for Collection of Submandibular Saliva from Dentate Patients," Br. Dent. J. 162:148-150(1987) and Oliveby et al, "Studies on Fluoride Concentrations in Human Submandibular/Sublingual Saliva and their Relation to Flow Rate and Plasma Fluoride Levels," J. Dent. Res. 68:146-149(1989) shortened the time and reduce the number of steps involved in the construction of such devices, a significant time is still required to construct these collectors. Further drawbacks to such appliances include their lack of standarization when sampling different subjects, especially adults and children.
Universal appliances have been proposed. However, most universal appliances require individual adaptation with impression material (Battistone et al, "The Free Amino Acid Composition of Human Saliva," Arch. Oral Biol. 3:161-170(1961); Block et al "A Method of Submaxillary Saliva Collection without Cannulization," N.Y. State Dent. J. 28:1160-118(1962); Marder et al, "A New Stabilizing Device for the More Accurate Collection of Submaxillary Saliva," N.Y. State Dent. J. 31:301-303(1965) and Coudert et al, "A New Appliance for the Collection of Human Submandibular Saliva," Arch. Oral Biol. 31:411-413(1986)).
An appliance designed by Truelove et al, "Simplified Method for Collection of Pure Submandibular Saliva in Large Volumes," J. Dent. Res. 46:1400-1403(1967) requires that certain tongue movements and swallowing patterns be performed by the subjects. This necessary method of use poses a difficulty in dealing with children and handicapped persons. In addition, some difficulties may arise in edentulous patients.
Systems similar to those described above also share a disadvantage in their relative bulk. When positioned within a patient's mouth, the size of these devices often distort measurements of unstimulated saliva flow, which has to be collected under resting conditions, with the subject feeling as comfortable as possible and minimizing the subjects perception of foreign bodies in their mouth.
While the use of a micropipette suction device has proven generally successful (Tylenda et al, "Evaluation of Submandibular Salivary Flow Rate in Different Age Groups" J. Dent. Res. 67:1225-1228(1988)), associated drawbacks include frequent loss of part of the saliva sample into the suction device and the safety risk produced by the use of a glass micropipette. One particular system which utilizes micropipettes has been found to cause difficulty in use during continuing gustatory stimulation (Pedersen et al, "Age-dependent Decreases in Human Submandibular Gland Flow Rates Under Resting and Post-Stimulation Conditions," J. Dent. Res. 64:822-825(1985)).
The present invention is an improvement over prior art saliva sampling devices which provides for easy sampling and high reliability and standardization among subjects.